Role of ATP-sensitive K+ channels in ischemic preconditioning of skeletal muscle against infarction

1997 ◽  
Vol 273 (1) ◽  
pp. H44-H51 ◽  
Author(s):  
C. Y. Pang ◽  
P. Neligan ◽  
H. Xu ◽  
W. He ◽  
A. Zhong ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Ischemic Preconditioning ◽  
Ischemia Reperfusion ◽  
Energy Charge ◽  
Katp Channels ◽  
High Energy ◽  
Intraarterial Infusion ◽  
Muscle Flaps ◽  
Charge Potential

We studied the role and mechanism of ATP-sensitive K+ (KATP) channels in ischemic preconditioning (IPC) of skeletal muscle against infarction in vivo. Surgically denervated, noncontractile latissimus dorsi muscle flaps in pentobarbitone-anesthetized pigs were assigned to nine groups: control; IPC (3 cycles of 10-min ischemia/reperfusion); preischemic lemakalim (LMK, 0.18 mg/muscle); postischemic LMK; sodium 5-hydroxydecanoate (5-HD, 27 mg/muscle) before IPC; glibenclamide (Glib 0.3 mg/kg iv) before IPC; 5-HD before preischemic LMK; 5-HD before ischemia; and Glib before ischemia. Except for Glib, all drugs were delivered to each muscle by 10-min local intraarterial infusion to avoid systemic effects. All muscle flaps underwent 4 h of global ischemia. Infarction was assessed at 48 h of reperfusion. In a separate study, muscle biopsies were taken before, during, and after ischemia for assay of high-energy phosphate and lactate contents and myeloperoxidase (MPO) activity. It was observed that muscle infarction in the IPC (24 +/- 2%) and preischemic LMK (21 +/- 2%) groups were smaller (P < 0.05) than that in the control (42 +/- 2%). The anti-infarction effect of IPC and LMK was blocked by 5-HD or Glib. IPC and preischemic LMK caused a higher (P < 0.05) muscle content of ATP and energy charge potential, a lower (P < 0.05) muscle content of lactate during ischemia, and a lower (P < 0.05) muscle MPO activity throughout 16 h of reperfusion compared with the control. These observations indicated for the first time that KATP channels are also involved in the anti-infarction effect of IPC in noncontractile skeletal muscle in vivo. Presently, the cause and importance of energy-sparing and neutrophil-inhibitory effects of IPC and LMK are not known.

Effector mechanism of adenosine in acute ischemic preconditioning of skeletal muscle against infarction

1997 ◽  
Vol 273 (3) ◽  
pp. R887-R895 ◽  
Author(s):  
C. Y. Pang ◽  
P. Neligan ◽  
A. Zhong ◽  
W. He ◽  
H. Xu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Ischemic Preconditioning ◽  
Energy Charge ◽  
Muscle Flap ◽  
Katp Channels ◽  
Channel Blockers ◽  
Muscle Flaps ◽  
Latissimus Dorsi Muscle Flap ◽  
Effector Mechanism ◽  
A1 Receptor

We used adenosine A1 receptor agonist N6-1(phenyl-2R-isopropyl)-adenosine (PIA), A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), and ATP-sensitive K+ (KATP) channel blockers sodium 5-hydroxydecanoate (5-HD) and glibenclamide (Glib), as probes to investigate the role and mechanism of adenosine in ischemic preconditioning (IPC) of noncontractile skeletal muscle against infarction, using the pig latissimus dorsi muscle flap model. Except for Glib, all drugs were delivered to each muscle flap by 10-min local intra-arterial infusion to avoid systemic effects. Muscle flaps that were subjected to 4 h of global ischemia and 48 h of reperfusion sustained 40 +/- 2% infarction. IPC with three cycles of 10 min ischemia and reperfusion, preischemic adenosine, or PIA treatment reduced (P < 0.05) muscle infarction to 24 +/- 2, 18 +/- 2, and 24 +/- 2%, respectively. The anti-infarction effect of IPC and adenosine was blocked by DPCPX, 5-HD, and Glib (P < 0.05). Preischemic adenosine treatment also maintained higher muscle contents of phosphocreatine, ATP, and energy charge potential and lower muscle contents of dephosphorylated metabolites and lactate during ischemia and a lower muscle myeloperoxidase (MPO) activity during reperfusion compared with the control (P < 0.05). Preischemic adenosine treatment did not increase muscle content of adenosine during ischemia or reperfusion. Furthermore, adenosine given at the onset of reperfusion was not effective in attenuating muscle MPO activity or infarction. Taken together, these observations indicate that adenosine, through A1 receptors, initiates the mechanism of IPC with postreceptor involvement of KATP channels in skeletal muscle. However, adenosine is unlikely to play a key role in the effector mechanism. Presently, the cause and role of energy sparing and neutrophil inhibitory effects associated with the anti-infarction effect of preischemic adenosine treatment are unknown.

Anaerobic energy provision in aged skeletal muscle during tetanic stimulation

1991 ◽  
Vol 70 (4) ◽  
pp. 1787-1795 ◽  
Author(s):  
C. B. Campbell ◽  
D. R. Marsh ◽  
L. L. Spriet
Keyword(s):  
Skeletal Muscle ◽  
Energy Demand ◽  
Energy Charge ◽  
High Energy ◽  
High Energy Phosphates ◽  
Fischer 344 ◽  
Charge Potential ◽  
Anaerobic Energy ◽  
Gastrocnemius Muscles

The effect of age on skeletal muscle anaerobic energy metabolism was investigated in adult (11 mo) and aged (25 mo) Fischer 344 rats. Hindlimb skeletal muscles innervated by the sciatic nerve were stimulated to contract with trains of supramaximal impulses (100 ms, 80 Hz) at a train rate of 1 Hz for 60 s, with an occluded circulation. Soleus, plantaris, and red and white gastrocnemius (WG) were sampled from control and stimulated limbs. All muscle masses were reduced with age (9-13%). Peak isometric tensions, normalized per gram of wet muscle, were lower throughout the stimulation in the aged animals (28%). The potential for anaerobic ATP provision was unaltered with age in all muscles, because resting high-energy phosphates and glycogen contents were similar to adult values. Anaerobic ATP provision during stimulation was unaltered by aging in soleus, plantaris, and red gastrocnemius muscles. In the WG, containing mainly fast glycolytic (FG) fibers, ATP and phosphocreatine contents were depleted less in aged muscle. In situ glycogenolysis and glycolysis were 90.0 +/- 4.8 and 69.3 +/- 2.6 mumol/g dry muscle (dm) in adult WG and reduced to 62.3 +/- 6.9 and 51.5 +/- 5.5 mumol/g dm, respectively, in aged WG. Consequently, total anaerobic ATP provision was lower in aged WG (224.5 +/- 20.9 mumol/g dm) vs. adult (292.6 +/- 7.6 mumol/g dm) WG muscle. In summary, the decreased tetanic tension production in aged animals was associated with a decreased anaerobic energy production in FG fibers. Reduced high-energy phosphate use and a greater energy charge potential after stimulation suggested that the energy demand was reduced in aged FG fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Role and mechanism of PKC in ischemic preconditioning of pig skeletal muscle against infarction

2000 ◽  
Vol 279 (2) ◽  
pp. R666-R676 ◽  
Author(s):  
Richard A. Hopper ◽  
Christopher R. Forrest ◽  
Huai Xu ◽  
Anguo Zhong ◽  
Wei He ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Ischemia Reperfusion ◽  
Muscle Blood Flow ◽  
Signal Transduction Pathway ◽  
Muscle Flap ◽  
Polymyxin B ◽  
Myeloperoxidase Activity ◽  
Muscle Flaps ◽  
Arterial Blood

Protein kinase C (PKC) inhibitors, chelerythrine (Chel, 0.6 mg) and polymyxin B (Poly B, 1.0 mg), and PKC activators, phorbol 12-myristate 13-acetate (PMA, 0.05 mg) and 1-oleoyl-2-acetyl glycerol (OAG, 0.1 mg), were used as probes to investigate the role of PKC in mediation of ischemic preconditioning (IPC) of noncontracting pig latissimus dorsi (LD) muscles against infarction in vivo. These drugs were delivered to each LD muscle flap (8 × 12 cm) by 10 min of local intra-arterial infusion. It was observed that LD muscle flaps sustained 43 ± 5% infarction when subjected to 4 h of global ischemia and 24 h of reperfusion. IPC with three cycles of 10 min ischemia-reperfusion reduced muscle infarction to 25 ± 3% ( P < 0.05). This anti-infarction effect of IPC was blocked by Chel (42 ± 7%) and Poly B (37 ± 2%) and mimicked by PMA (19 ± 10%) and OAG (14 ± 5%) treatments ( P < 0.05), given 10 min before 4 h of ischemia. In addition, the ATP-sensitive K+ (KATP) channel antagonist sodium 5-hydroxydecanoate attenuated ( P < 0.05) the anti-infarction effect of IPC (37 ± 2%), PMA (44 ± 17%), and OAG (46 ± 9%). IPC, OAG, and Chel treatment alone did not affect mean arterial blood pressure or muscle blood flow assessed by 15-μm radioactive microspheres. Western blot analysis of muscle biopsies obtained before (baseline) and after IPC demonstrated seven cytosol-associated isoforms, with nPKCɛ alone demonstrating progressive cytosol-to-membrane translocation within 10 min after the final ischemia period of IPC. Using differential fractionation, it was observed that nPKCɛ translocated to a membrane compartment other than the sarcolemma and/or sarcoplasmic reticulum. Furthermore, IPC and preischemic OAG but not postischemic OAG treatment reduced ( P < 0.05) muscle myeloperoxidase activity compared with time-matched ischemic controls during 16 h of reperfusion after 4 h of ischemia. Taken together, these observations indicate that PKC plays a central role in the anti-infarction effect of IPC in pig LD muscles, most likely through a PKC-KATPchannel-linked signal-transduction pathway.

scholarly journals Inhibiting myosin-ATPase reveals a dynamic range of mitochondrial respiratory control in skeletal muscle

2011 ◽  
Vol 437 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Christopher G. R. Perry ◽  
Daniel A. Kane ◽  
Chien-Te Lin ◽  
Rachel Kozy ◽  
Brook L. Cathey ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Dynamic Range ◽  
Energy Charge ◽  
Respiratory Control ◽  
Basic Research ◽  
Dependent Manner ◽  
Atpase Inhibitor ◽  
Wide Range ◽  
The Impact

Assessment of mitochondrial ADP-stimulated respiratory kinetics in PmFBs (permeabilized fibre bundles) is increasingly used in clinical diagnostic and basic research settings. However, estimates of the Km for ADP vary considerably (~20–300 μM) and tend to overestimate respiration at rest. Noting that PmFBs spontaneously contract during respiration experiments, we systematically determined the impact of contraction, temperature and oxygenation on ADP-stimulated respiratory kinetics. BLEB (blebbistatin), a myosin II ATPase inhibitor, blocked contraction under all conditions and yielded high Km values for ADP of >~250 and ~80 μM in red and white rat PmFBs respectively. In the absence of BLEB, PmFBs contracted and the Km for ADP decreased ~2–10-fold in a temperature-dependent manner. PmFBs were sensitive to hyperoxia (increased Km) in the absence of BLEB (contracted) at 30 °C but not 37 °C. In PmFBs from humans, contraction elicited high sensitivity to ADP (Km<100 μM), whereas blocking contraction (+BLEB) and including a phosphocreatine/creatine ratio of 2:1 to mimic the resting energetic state yielded a Km for ADP of ~1560 μM, consistent with estimates of in vivo resting respiratory rates of <1% maximum. These results demonstrate that the sensitivity of muscle to ADP varies over a wide range in relation to contractile state and cellular energy charge, providing evidence that enzymatic coupling of energy transfer within skeletal muscle becomes more efficient in the working state.

Ischemia/reperfusion-induced changes in intracellular free Ca2+ levels in rat skeletal muscle fibers – an in vivo study

2000 ◽  
Vol 440 (2) ◽  
pp. 302-308 ◽  
Author(s):  
Tamás Ivanics ◽  
Zsuzsa Miklós ◽  
Zoltán Ruttner ◽  
Sándor Bátkai ◽  
Dick W. Slaaf ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Ischemia Reperfusion ◽  
Muscle Fibers ◽  
In Vivo Study ◽  
Rat Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Induced Changes

Sequential ischemia/reperfusion results in contralateral skeletal muscle salvage

1996 ◽  
Vol 270 (4) ◽  
pp. H1407-H1413 ◽  
Author(s):  
S. K. Liauw ◽  
B. B. Rubin ◽  
T. F. Lindsay ◽  
A. D. Romaschin ◽  
P. M. Walker
Keyword(s):  
Skeletal Muscle ◽  
Preliminary Analysis ◽  
Adenine Nucleotides ◽  
Ischemia Reperfusion ◽  
Gracilis Muscle ◽  
Muscle Group ◽  
Muscle Ischemia ◽  
Muscle Necrosis ◽  
Shock Proteins

Sequential ischemia/reperfusion in a paired canine gracilis muscle model resulted in significant muscle salvage. In this model, one randomly chosen gracilis muscle was subjected to 5 h of ischemia followed by 48 h of in vivo reperfusion. The contralateral (second) muscle was then made ischemic and reperfused using the same protocol. Muscle necrosis was determined at the end of 48 h of reperfusion. A mean 60% reduction in muscle necrosis was observed in the second group of muscles. Analysis of tissue adenine nucleotides indicated that significant sparing of ATP utilization occurred in the second muscle group during ischemia. Preliminary analysis of tissue heat shock proteins (HSP) showed that the second group of muscles had a different pattern of HSP expression before the onset of ischemia. The results suggest that reduced ATP utilization and altered HSP expression in the second muscle play a role in the tissue salvage observed in this sequential muscle ischemia model.

scholarly journals Ischemic Preconditioning Prevents Endothelial Injury and Systemic Neutrophil Activation During Ischemia-Reperfusion in Humans In Vivo

Circulation ◽  
2001 ◽  
Vol 103 (12) ◽  
pp. 1624-1630 ◽  
Author(s):  
Rajesh K. Kharbanda ◽  
Mark Peters ◽  
Benjamin Walton ◽  
Mia Kattenhorn ◽  
Michael Mullen ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Ischemia Reperfusion ◽  
Neutrophil Activation ◽  
Endothelial Injury
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